Sunny with pleasantly warm air temperatures (feeling like 21 °C once we account for wind), yet at 18 °C the sea remains several degrees colder than the air at Arnold. The majority of surfers will need a spring wetsuit though a summer suit or even a shorty may suffice for a short session.

Arnold water temperatures peak in the range 16 to 20°C (61 to 68°F) on around the 5th of September and are at their coldest on about the 5th of February, in the range 12 to 16°C (54 to 61°F). The warmest seasonal water temperatures at Arnold at the beginning of September lend themselves to a 4/3mm wetsuit or a 3/2mm suit and 3mm neoprene boots. The coldest water temperatures at Arnold at the beginning of February are ideally suited to a 4/3mm wetsuit + 3mm boots, although a 5/3mm wetsuit may be preferable for longer sessions and cold windy days.